دانلود کتاب روش ها و پروتکل های R-Loops – زیست شناسی مولکولی

Double-stranded DNA–RNA hybrids and R-loops, the molecular structures comprised of such hybrids together with a displaced single DNA strand, are secondary nucleic acid conformations frequently formed in the genomes of all living organisms. Generally, both the terms (DNA–RNA hybrids and R-loops) are used interchangeably as, in the majority of biological contexts, DNA–RNA hybrids are likely to be present in the form of R-loops, even though this is not necessarily the case for certain physiological settings. R-loops or DNA-RNA hybrids can emerge as intermediates during a number of key biological processes such as retro-transposition, class switching recombination, telomere homeostasis, or certain steps of transcription of particular genes, therefore playing specific roles in cellular metabolism. However, in many cases, R-loops may also be unscheduled or abnormally persistent, representing an important source of genomic stress and instability. This adds an additional physiological relevance to these structures, provided that genome instability is a hallmark of cancer cells and frequently associated with a number of genetic diseases, including neurodegenerative conditions and cancer-prone syndromes. Altogether, the potential roles of R-loops in the regulation of cellular processes, and their strong influence on genome dynamics, have attracted a growing interest in these structures in different areas of molecular and cellular biology as well as biomedicine.